/Engine/Source/Editor/Sequencer/Public/ISequencer.h
typedef TMulticastDelegate_TwoParams< void, const [FMovieSceneChannelMetaData](API\Runtime\MovieScene\Channels\FMovieSceneChannelMetaData) *MetaData, [UMovieSceneSection](API\Runtime\MovieScene\UMovieSceneSection) * > FOnChannelChanged